1. Field of the Invention
The present invention relates to exercise equipment, in particular a weight machine that is typically used to perform chest press, incline press, shoulder press and rowing exercise routines.
2. Description of Related Art
Exercise machines typically have a series of cables and pulleys that mechanically couple a moveable exercise member to a weight stack. The weight stack is lifted by pushing or pulling the exercise member from a rest position. One such type of exercise machine employs a press arm as the exercise member, which is coupled to a weight stack by a cable/pulley assembly. The press arm and cable/pulley assembly are supported by a frame that allows the user to exercise while in a seated position. The weight stack is lifted by moving the press arm away from the user, thus providing the same exercising motion as performed with a conventional "free weight" bench press.
The distance between the back pad of the seat and the press arm is typically fixed. Therefore, users of different physical size will have different starting positions. The different starting positions will vary the range of lifting motion for each user, thereby affecting the impact of the exercise routine.
It is preferable to provide a press arm machine with an adjustable back pad that allows the user to perform variable pressing exercises from different starting positions. For some exercise routines, it is more desirable for the user to be in an inclined position, for other routines the user may want to be in a more upright position. Compensating for various users, or different starting positions, typically requires moving the press arm to a new resting position. Various mechanisms have been developed for providing a starting position adjustment for press arm exercises. Many of these prior art "pre-stretch" adjustment mechanisms provide an adjustment for the cable system, but do not provide an adjustable stop for the press arm. A mechanism of this type is shown in this inventor's U.S. Pat. No. 5,263,915.
Another mechanism for adjusting a rest position of a press arm is shown in U.S. Pat. No. 5,236,406. In this mechanism, the press arm is selectively positioned with respect to a pivoting block assembly. All cable paths are unaffected by a change in the rest position of the press arm. This particular mechanism, however, is relatively complex and therefore expensive to manufacture. The adjustment pin is necessarily placed at a relatively high position above the operator's head and is therefore somewhat difficult to adjust from a sitting position. Placement of the adjustment pin near the pivot point of the press arm also places a high shear load on the adjustment pin during the performance of press exercises.
It is desirable to provide a press arm exercise machine in which the press arm may be simply and conveniently adjusted to a new starting position with a positive stop while maintaining the cable system in a slack free condition.